Quick release detachable wheels

ABSTRACT

A quick release detachable wheel hub assembly is shown for a lightweight manual wheelchair. The wheelchair wheels mount on exterior hubs and rotate therewith. The inner face out of each of the exterior hubs mates with an opposing outer face of interior hubs. One of the opposing faces on the hubs has a projection or a plurality of projections which fit snugly into corresponding openings on the opposing face of the other hub when the opposing faces of the hubs are mated. The interior hubs are mounted and rotate on detachable axles which screw into the wheelchair frame. A quick release, removable locking pin is inserted through the center of the hubs and into detachable axle and locked in place and thereby causing the hubs to be locked and rotate together. The wheels are quickly detached by simply removing the locking pins and pulling apart the hubs.

[0001] This application is a continuation in part of my now pending U.S.patent application Ser. No. 09/921,498 filed on Aug. 2, 2002.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to the field ofwheelchairs and, more specifically, to an electrical braking system andquick release, detachable wheels for manual wheelchairs.

[0004] 2. Description of the Related Prior Arts

[0005] Numerous types of braking mechanisms for manual wheelchairs areknown in the art. The most typical manual wheelchair brake is a manual“over center” locking device which is activated by a lever arm and, whenforced into its locking position, presses a braking member against thesurface of the wheelchair tire creating a frictional braking action.Several factors mitigate against the usefulness and reliability of thesetypes of brakes. Loss of tire pressure reduces the frictional forceexerted by the crossbar on the tire and hence reduces the brakingeffect. A significant air pressure loss leaves these brakes useless.During transfer in and out of the chair, this type of brake allows thetire to slide underneath the crossbar and the wheelchair to move.Similarly, the brakes are ineffective and will not adequately hold thewheelchair on an incline. Other types of manual brakes include calipertype brakes manually activated with a lever arm mounted to a cable andbrake assembly causing brake pads to press against the rim of thewheelchair wheel.

[0006] In these types of brakes, the frictional braking force exerted isdirectly related to the manual force which must be exerted on the leverarm by the brake operator to activate the brake. Wheelchair users whohave arm or hand limitations may not be physically able to operate thesebrakes. These braking mechanisms only apply a braking force to onewheel. If an equal braking force is desired on both wheels, the user isrequired to use both arms and attempt to apply an equal force to bothlever arms at the same time. This is difficult, if not impossible.Wheelchair frame and wheel design most often require the placement ofthe lever arms on the frame of the wheelchair near the user's knees. Theplacement of these lever arms interferes with the user's transfer in andout of the wheelchair. These lever arms require lifting the user's bodyin order to clear the lever during transfer.

[0007] A patent to Ross and Gunther, U.S. Pat. No. 5,358,266 describes aplate attached to a braking member, which applies a braking frictionalforce to the wheelchair tire when electronically activated by a solenoidrod. The solenoid rod is activated by means of a switch attached to theseat of the wheelchair. When the wheelchair user is raised out of theseat, the switch is activated and operates the braking mechanism. Alsodisclosed in this patent is a manually activated lever arm to operatethe same braking member when the wheelchair user is seated. The samedeficiencies discussed above apply to this wheelchair while thewheelchair user is seated. A wheelchair user with arm or handlimitations may not be able to operate the hand lever and the lever armbraking mechanism to apply a braking force to one wheel. In addition,the position of the lever arm may interfere with transfer in and out ofthe wheelchair.

[0008] Electric wheelchairs with various forms of braking means arecommon in the prior art. These braking means include gear reductionmechanisms, electromagnetic braking by means of a resistance applied tothe electric motors, electronically activated frictional brakingmechanisms where a solenoid is electrically energized to move brakeshoes into frictional contact with a brake drum, and conventional manualbrakes operated by a lever mechanism. These electric wheelchairs areheavy, cumbersome, difficult to transport, and do not promote physicalactivity by the user.

[0009] Wheelchair users have reason to frequently remove the wheels fromtheir wheelchairs. It is often done for storage purposes, for brakeadjustment, for wheel repair, and for wheel exchange. For example, inorder to store a wheelchair in a vehicle, it is often desirable toremove the wheels.

[0010] Heretofore, the wheels on manual wheelchairs and other types ofwheelchairs have been attached to the wheelchair frame by some type ofhub with the wheels secured to the hub with nuts and bolts. In order toremove the wheels from the wheelchair, it has been necessary to unscrewand remove each of the nuts and bolts securing the wheel to the hub.This is a time consuming and cumbersome process. Once again, wheelchairusers who have arm or hand limitations may not be physically able toremove the nuts and bolts.

[0011] More recently, it has become common in the art to attach wheelsto manual wheelchairs using quick release locking pins which hold thewheel to the axle. In this type of design, it is difficult to also havea braking means on the wheelchair wheel other than the manual “overcenter” locking device which presses a braking member against thesurface of the tire as described herein. Heretofore, other brakes havebeen ineffective on wheelchairs with quick release locking pins becausethe braking means had to be released and moved or disassembled in orderto remove the wheel and thereby defeating the purpose of the quickrelease locking pin.

[0012] It is desirable to have a lightweight, manual wheelchair with aneffective easily operatable electronic braking mechanism and, at thesame time, quick release detachable wheels.

SUMMARY OF THE INVENTION

[0013] It is an object of this invention to provide an electronicallyactivated braking system for a lightweight, manual wheelchair, whichallows the wheelchair to maintain its lightweight and maneuverabilitycharacteristics.

[0014] It is a further object of this invention to have anelectronically activated braking system for manual wheelchairs whicheliminates the need for users of the wheelchair to manually operatebrakes by means of a lever mechanism.

[0015] It is a further object of this invention to provide a brakingsystem for manual wheelchairs, which provides equal braking force toboth wheels of a wheelchair simultaneously.

[0016] It is a further object of this invention to provide a brakingmeans for a manual wheelchair, which can be activated without the use ofa manually operated lever that interferes with transfer in and out ofthe wheelchair by the user.

[0017] It is a further object of this invention to provide a brakingmeans for manual wheelchairs, which eliminates movement of thewheelchairs on inclines and during transfer in and out of the wheelchairby the user.

[0018] It is a further object of this invention to provide a brakingmeans for manual wheelchairs, which allows for detaching the wheelchairwheels without disturbing the braking means.

[0019] It is a further object of this invention to provide for quickrelease, easily detachable wheels.

[0020] It is a further object of this invention to provide fordetachable wheels, which eliminates the need for users of the wheelchairto unscrew numerous nut and bolt combinations in order to remove thewheel.

[0021] It is a further object of this invention to provide for quickrelease, easily detachable wheels which allow the wheels to be removedwithout removing the disk and brake assembly.

[0022] In order to achieve these objectives, this invention provides foran electronic braking system, which is comprised of a braking means, acable pulley system for activating the braking means, a DC lineractuator with actuator rod connected to the cable pulley system, amotion limit switch, a rechargeable twelve-volt battery electronicallyconnected to the DC actuator, and a double throw control switchelectronically connected to the battery for activating the batterypower.

[0023] It is anticipated that the preferred braking means is acaliper-type brake positioned to clamp onto a metal disk mounted axiallyto a hub which rotates on the axle of each wheelchair wheel. The hub onwhich the disk is mounted interlocks with the hub on which thewheelchair wheel is mounted. The interlocking hubs are locked togetherwith a locking pin, which extends axially through the center of themated hubs such that the hubs are locked and rotate together when thewheelchair wheel is turned.

[0024] The locking pin is equipped with retractable nipples which, whenextended, hold the locking pin securely in place. The retractablenipples are spring biased in the extended position and are activated bya push button at one end of the locking pin which releases the springand allows the nipples to retract. When the nipples are in the retractedposition, the locking pin can be removed simply by sliding it out of theaxle. This allows the wheelchair wheel to be removed since there is nolonger anything holding the mated hubs together.

[0025] The braking means for each wheel are connected to opposite endsof a cable wire. The cable wire passes around a pulley such thatdisplacement of the pulley provides equal force and displacement to saidopposite ends of the cable wire. The ends of the cable wire are directedthrough small openings in a mounting bracket. The openings are spaced adistance equal to the diameter of the pulley so the cable wire remainsparallel as it extends from the pulley through said openings. A circularpulley cap is placed concentrically over the pulley. The vertical sideof the pulley cap has two openings to allow for the passage of the wirecable into the pulley cap through the first opening, around the pulleyand out the second opening. The pulley cap, pulley, and cable wireassembly is then connected to the outer end of the actuator rod by acoupling bracket.

[0026] The DC linear actuator is mounted on the wheelchair in a mannerto allow the actuator rod to extend and displace the pulley and cablewire in line with the actuator rod's axis. The DC linear actuator iselectronically powered by a twelve-volt rechargeable battery mounted tothe wheelchair. The battery power is activated by a double throw controlswitch mounted to the wheelchair in a position where it is easilyaccessed by both the wheelchair user and a person assisting thewheelchair user.

[0027] The double throw toggle switch can be thrown in two differentdirections. When the double throw toggle switch is thrown in the firstdirection, it will cause the actuator rod to retract, pulling the pulleyand cable wires and activating the braking force. When the toggle switchis thrown in the second direction, it will cause the actuator rod toextend, pushing the pulley and cable wire and deactivating the brakingforce.

[0028] In order to limit the tension in the cable wire, a motion limitswitch can be added to the electrical brake system. The motion limitswitch is wired into the circuit between the double throw toggle switchand said DC linear actuator. The motion limit switch is activated bydisplacement of the actuator rod in the direction which pulls the cablewire and activates the braking means. Once a selected braking force isattained, the motion limit switch opens the circuit and stops thedisplacement of the actuator rod.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is a elevational side view of a manual wheelchair depictinga caliper braking mechanism mounted to the wheelchair frame andpositioned to clamp onto a metal disk mounted axially to the hub of thewheelchair wheel.

[0030]FIG. 2A is an enlarged exploded perspective view depicting thelocking pin, wheelchair wheel, hub, disk, and axle assembly which has aspring biased push button type locking pin and first interlocking hubdesign.

[0031]FIG. 2B is an enlarged exploded perspective view depicting thelocking pin, wheelchair wheel, hub, disk, and axle assembly wherein thelocking pin is equipped with a lever which activates an expandable tip.

[0032]FIG. 2C is an enlarged exploded perspective view depicting FIG. 2Afrom the opposite angle.

[0033]FIG. 2D is an enlarged exploded perspective view depicting thelocking pin, wheelchair wheel, hub, disk, and axle assembly. This figuredepicts a second interlocking hub design.

[0034]FIG. 2E is an enlarged exploded perspective view depicting FIG. 2Dfrom the opposite angle.

[0035]FIG. 3 is a bottom view of the wheelchair seat depicting thetoggle switch, the battery recharging outlet, the electrical wiring, thetwelve-volt rechargeable battery, the DC linear actuator, the cable wireand pulley assembly, and the motion limit switch.

[0036]FIG. 4 is an enlarged perspective view depicting the caliperbraking mechanism.

[0037]FIG. 5 is an exploded perspective view depicting the cable wireand pulley assembly and actuator rod mount.

[0038]FIG. 6 is a bottom view of the cable wire, pulley, and actuatorrod assembly brackets and the motion limit switch.

[0039]FIG. 7 is a elevational side view of the coupling bracket.

[0040]FIG. 8 is an electrical circuit diagram illustrating theelectrical control circuit of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0041] Referring to FIG. 1, a lightweight manual wheelchair 10 isequipped with a solid seat base 11, seat cushion 12, and seat back 13mounted between first and second wheelchair wheels 24 generally to aframe 14. The frame 14 has a vertical component 15, a side horizontalcomponent 16, a frontal curved component 17 and a lower curved component20. A footrest 19 is mounted at the frontal extremity of the lowercurved component 20 of the frame 14. First and second caster wheels 21are pivotally mounted toward the frontal extremity of the lower curvedcomponent 20 of the frame 14. The manual wheelchair 10 is symmetricalabout a centre line and the opposed side is identical to the sidevisible in FIG. 1. Thus, when the first and second of numbered items arereferred to without the second item being shown, it can be appreciatedthat the second numbered item is identical to the first but on theopposite side of the wheelchair.

[0042] First and second caliper brakes 18 are mounted to extensionplates (not shown) which are in turn mounted to the frame 14. Thecaliper brakes 18 are positioned to clamp onto first and second disks 22(see FIGS. 1 and 4). In the preferred embodiment of this invention, thefirst and second caliper brakes 18 are manufactured by Hayes/HMX, modelnumber BR3920. However, numerous other cable actuated caliper brakes areavailable on the market and can be used in this invention. The first andsecond wheelchair wheels 24 can be detached without removal of the firstand second disks 22 or the first and second caliper brakes 18.

[0043] Referring to FIGS. 2A through 2E, the first and second disks 22are concentrically mounted to the inner face 83 first and second diskhubs 23 by means of a plurality of screws 29 passing through radiallyspaced interiorly threaded, aligned holes 51 in the first and seconddisk hubs 23 and the first and second disks 22. In the preferredembodiment, as shown in FIGS. 2A, 2B, and 2C, the screws 29 are Allenscrews where the heads 33 of the screws 29 extend from the outervertical faces 27 of the first and second disk hubs 23 and are securedon the opposite end by nuts 38. In a second preferred embodiment, asshown in FIGS. 2D and 2E, the screws 29 are of a length insufficient toextend beyond the outer vertical faces 27 of the first and second diskhubs 23.

[0044] The first and second disk hub 23 and disk 22 assemblies areconcentrically mounted to outer ends of first and second detachable axlepieces 80 and rotate thereon. The first and second detachable axlepieces 80 are tubular with a smooth surface portion 82 at their outerend and a exteriorly threaded portion 84 at their inner end. The smoothsurface portion 82 and the exteriorly threaded portion 84 are divided bya flange 86.

[0045] The first and second detachable axle pieces 80 are mounted to theframe 14 of the wheelchair 10 (see FIG. 1) by screwing the exteriorlythreaded portion 84 into a tubular axle 25. As shown in FIG. 3, thetubular axle 25 is clamped to the first and second lower curvedcomponents 20 of the frame 14 (See FIG. 1) at its rear extremity byfirst and second frame clamps 72.

[0046] Referring again to FIGS. 2A through 2E, the outer ends of thetubular axle 25 have mounting heads 88. Each mounting head 88 has athreaded bore 90 with a diameter sufficient to accept and secure theexteriorly threaded portion 84 of the first and second detachable axlepieces 80 therein. The first and second detachable axle pieces 80 aremounted to the tubular axle 25 by screwing the exteriorly threadedportion 84 into the threaded bore 90.

[0047] The first and second disk hub 23 and disk 22 assemblies aresecured to the first and second detachable axle pieces 80 by means of aclip ring 39. The clip ring 39 is spring biased to close around and fitin to a circumferential groove 78 cut into the smooth surface portion 82of the first and second detachable axle pieces 80 at their extreme outerend. In order to allow the first and second disk hub 23 and disk 22assemblies to rotate on the first and second detachable axle pieces 80,the smooth surface portion 82 of the first and second detachable axlepieces 80 extend axially through a tubular opening 92 at the center ofthe first and second disk hubs 23 and the outer face of flange 86 abutsa concentric circular shoulder 87 (see FIGS. 2C and 2D) on the innerface 83 of the first and second disk hubs 23 with a spacer ring 94between. The spacer ring 94 prevents frictional contact between theouter face of flange 86 and the circular shoulder 87 on the inner faceof the first and second disk hubs 23. In the preferred embodiment, thespacer ring 94 is a Delrin washer. However it is anticipated that othersmooth, durable material can be substituted.

[0048] Referring to FIGS. 2A, 2B, and 2E, the outer vertical face 27 ofthe first and second disk hub have a concentric circular recessedportion 93 surrounding the tubular opening 92. The horizontal length ofthe smooth surface portion 82 of the detachable axle piece 80 issufficient to allow the smooth surface portion 82 to extend through thetubular opening 92 of the first and second disk hubs 23 and expose thecircumferential groove 78 on the opposite side of the first and seconddisk hubs 23 with minimal clearance at the concentric circular recessedportion 93. This allows the clip ring 39 to close around circumferentialgroove 78 within the concentric circular recessed portion 93.

[0049] As shown in FIGS. 2A through 2C, the first and second wheelchairwheels 24 are concentrically mounted on the first and second wheel hubs37. The inner surface 57 of the first and second wheelchair wheels 24(See FIG. 2C) is mounted flush against the outer vertical surface 70(See FIG. 2E) of the flanged inner portion 31 of the first and secondwheel hubs 37 and are secured to the first and second wheel hubs 37 byfirst and second nuts 45, which screw onto exteriorly threaded outerends 75 of the first and second wheel hubs 37. The first and secondwheel hubs 37 have a tubular opening 43 through their center. As shownin FIGS. 2A and 2B, an outer circular bearing assembly 61 is pressed fitinto the tubular opening 43 towards the outer end of the first andsecond wheel hubs 37.

[0050] As shown in FIGS. 2B, 2C, and 2D, an inner circular bearingassembly 79 is pressed fit into the tubular opening 43 at the inner endof the first and second wheel hubs 37. The outer bearing assembly 61 andinner bearing assembly 79 have inner rings 63 which turn within thebearing assemblies. The inner diameter of the inner rings 63 is equal tothe inner diameter of first and second detachable axle pieces 80. In thepreferred embodiment, the outer circular bearing assembly 61 and innercircular bearing assembly 79 are manufactured by NICE, Model No. 1616 DCTN or KYK, Model No. R-8-DDHA1(IB). However, it is anticipated thatother similar bearings could be used.

[0051] Referring again to FIGS. 2A through 2E, when the first and secondwheelchair wheels 24 are mounted to the wheel hub 37 and in turn mountedto the wheelchair 10 (See FIG. 1), the outer vertical faces 27 of thefirst and second disk hubs 23 interlock with inner faces 77 of theflanged inner portion 31 of the first and second wheel hubs 37. In thepreferred embodiment, as shown in FIGS. 2A, 2B, and 2C, the inner faces77 of the flanged inner portion 31 of the first and second wheel hubs 37are flat with a plurality of radially spaced holes 96 shown in FIG. 2C.The heads 33 of the plurality of screws 29 fit snugly into thecorresponding radially spaced circular holes 96 in the flanged innerportion 31 of the first and second wheel hubs 37. In an alternateembodiment, as shown in FIGS. 2D and 2E, the inner face 77 of theflanged inner portion 31 of the first and second wheel hubs 37 have araised surface 98 extending from the inner face 77. The raised surface98 is centered on the inner face 77 with parallel sides 100 extending tothe circumference of the inner face 77. The parallel sides 100 extendperpendicularly from the inner face. In this alternate embodiment, theouter vertical faces 27 of the first and second disk hubs 23 have achannel 102. The placement and dimensions of the channel 102 are toallow the raised surface 98 to fit snugly into the channel 102 withminimal clearance at all contiguous surfaces when the first and secondwheel hubs 37 are interlocked with the first and second disk hubs 23.

[0052] In the preferred embodiment, as shown in FIGS. 2A, 2B, and 2C,the interlocking of heads 33 within the radially spaced circular holes96 cause the first and second wheelchair wheels 24 and the first andsecond disks 22 to rotate together. In another alternate embodiment, asshown in FIGS. 2D and 2E, the interlocking of the raised surface 98 onthe inner face 77 of the first and second wheel hubs 37 with the channel102 in the outer vertical faces 27 of the first and second disk hubs 23cause the first and second wheelchair wheels 24 (See FIG. 1) and thefist and second disks 22 to rotate together.

[0053] Still referring to FIGS. 2A through 2E, in order to hold thefirst and second disk hubs and the first and second wheel hubs togetherwhen interlocked, first or second locking pins 35 a and 35 b (see FIGS.2A and 2B) extend axially through the center of the first and secondwheel hubs 37, the first and second disk hubs 23, and into the first andsecond detachable axle pieces 80. The first or second locking pins 35 aand 35 b have a diameter which allows the first or second locking pins35 a and 35 b to slide through the inner rings 63 of the outer circularbearing assembly 61 (See FIGS. 2A and 2B) and the inner circular bearingassembly 79 (See FIGS. 2C and 2D) and into the first and seconddetachable axle pieces 80 with minimal clearance.

[0054] The first and second wheelchair wheels 24 can be detached fromthe wheelchair 10 (See FIG. 1) without removing the first and seconddisks 22 or disturbing the first and second caliper brakes 18 byremoving the first and second locking pins 35 a or 35 b and separatingthe first and second wheel hubs 37 from the first and second disk hubs23.

[0055] In the preferred embodiment of the invention (see FIGS. 2A, 2C,2D, and 2E), the first and second locking pins 35 a have a push button47, a rod 49, an adjusting nut 53, and a set of retractable nipples 55.The push button 47 is spring biased in the released position, causingthe retractable nipples 55 to extend from the rod 49. When the pushbutton 47 is depressed, the retractable nipples 55 retract into the rod49. The first and second locking pins 35 a can be inserted through theinner ring 63 of the outer circular bearing assembly 61 and into thetubular openings 43 of the first and second wheel hubs 37 by depressingthe push button 47 and thereby causing the retractable nipples 55 toretract. When the first and second locking pins 35 a are furtherinserted through the first and second disk hubs 23 and into the firstand second detachable axle pieces 80 and the push button 47 is released,the retractable nipples 55 extend into grooves (not shown)circumferentially cut into the tubular interior surface (not shown) ofthe first and second detachable axle piece 80. The grooves (not shown)are of sufficient depth and width to allow the retractable nipples 55 toextend into the grooves (not shown) with minimal clearance. The grooves(not shown) are positioned in the first and second detachable axlepieces 80 to allow the retractable nipples 55 to extend into the firstand second grooves (not shown) when the first and second locking pins 35a are fully inserted into the first and second wheel hubs 37 such thatthe adjustable nut 53 contacts the outer surface of the outer circularbearing assembly 61. In the preferred embodiment, the first and secondlocking pins 35 a are QRP Quick Release Push Button (large/small) Axle,Model No. 21QRP11CDASN.

[0056] In an alternate embodiment of the invention, the length of theexteriorly threaded portion 84 of the first and second detachable axlepieces 80 is sufficient to allow the position of the retractable nipples55 on the first and second locking pins 35 a to extend beyond the innerlip 85 of the first and second detachable axle pieces 80 when the firstand second locking pins 35 a are fully inserted into the first andsecond wheel hubs 37 such that the adjustable nut 53 contacts the outersurface of the outer circular bearing assembly 61. Thus, when the firstand second locking pins 35 a are fully inserted and the push button 47is released, the retractable nipples 55 extend adjacent to the inner lip85 of the first and second detachable axle pieces 80 with minimalclearance and thereby holding the first and second locking pins 35 a inplace. In this embodiment, the first and second locking pins 35 a are,once again, QRP, Quick Release Push Button (large/small), Axle Model No.21QRP11CDASN.

[0057] In yet another embodiment of the invention (see FIG. 2B), thefirst and second locking pins 35 b have a release lever 65 at one end ofa rod 67, a spacer joint 69 between the release lever 65 and the rod 67,an expandable tip 71 attached to the other end of the rod 67, and awedging cap 73 attached to the expandable tip 71 opposite the rod 67.When the release lever 65 is rotated to the released position so that itextends parallel with the rod 67, the diameter of the expandable tip 71is not expanded and is equal to the diameter of the rod 67. When therelease lever 65 is rotated perpendicular to the rod 67, the wedging cap73 is pulled toward the release lever 65 causing the expandable tip 71to expand to a diameter greater than the diameter of the rod 67. Whenthe release lever 65 is in the released position, the first and secondlocking pins 35 b can be inserted through the inner ring 63 of the outercircular bearing assembly 61 and into the tubular opening 43 of thefirst and second wheel hubs 37. When the first and second locking pins35 b are inserted through the first and second wheel hubs 37, and intothe first and second detachable axle pieces 80 and the release lever 65is then rotated perpendicular to the rod 67, the expandable tip 71expands into and makes frictional contact with the interior surface (notshown) of the first and second detachable axle pieces 80. The frictionalforce created is great enough to hold the first and second locking pins35 b in place. The diameter of the spacer joint 69 is greater than theinner diameter of the inner ring 63 of the outer circular bearingassembly 61, such that when the first and second locking pins 35 b arefully inserted, the spacer joint 69 contacts the outer face of the outercircular bearing assembly 61. In this preferred embodiment, the lockingpin 35 b is the Ultra Axle, 0.50″ O.D. manufactured by Rousson Chamoux.

[0058] The first and second caliper brakes 18 are activated by pulling acable wire 26 (See FIGS. 4 and 5) attached to the caliper brakes 18 atfirst and second ends of the cable wire 26. The first and second ends ofthe cable wire 26 are directed to the first and second caliper brakes 18through a cable wire housing 28 which is attached to a nozzle 30 on thefirst and second caliper brakes 18. The first and second ends of thecable wire 26 are attached to the first and second caliper brakes 18,respectively, in typical fashion. The cable wire 26 passes through thenozzle 30 of the first and second caliper brakes 18 and into the cablewire housing 28. The cable wire housing 28 directs the cable wire 26 toa mounting bracket 32 (See FIG. 5). The mounting bracket 32 has avertical portion, and an upper horizontal portion. The mounting bracket32 is mounted to the bottom of the solid seat base 11 by two screws (notshown) passing through interiorly threaded aligned holes in the solidseat base 11 and upper horizontal portion of the mounting bracket 32.

[0059] The cable wire housing 28 is connected to the mounting bracket 32by means of first and second hollow connectors 34. The first ends of thefirst and second hollow connectors 34 fit snugly within first and secondcircular openings (not shown) in the mounting bracket 32 and the secondends of the first and second hollow connectors 34 fit snugly around thecable wire housing 28. The centers of said first and second circularopenings (not shown) are equidistant from the upper horizontal portionof the mounting bracket 32 and are horizontally spaced a distance equalto the diameter of the pulley 36. The diameter of the first and secondcircular openings (not shown) is sufficient to allow the first andsecond hollow connectors 34 to fit snugly and the cable wire 26 to passthrough first and second circular openings (not shown) within the firstand second hollow connectors 34. The cable wire 26 passes through thecircular openings in the mounting bracket 32 within the first and secondhollow connectors 34 and then passes around the pulley 36.

[0060] The pulley 36 and cable wire 26 assembly is covered with acircular pulley cap 40. The inner diameter of the circular pulley cap 40is of sufficient dimension to cover the pulley 36 and wire cable 26assembly with minimal clearance. The vertical side of the pulley cap 40has first and second openings 41 spaced to allow the cable wire 26 topass into the pulley cap 40 and around the pulley 36. In the preferredembodiment of this invention, the segments of the cable wire 26 onopposite sides of the pulley 36 between the pulley 36 and mountingbracket 32 are parallel. Both segments of the cable wire 26 areperpendicular to the vertical side of the mounting bracket 32.

[0061] The pulley cap 40, pulley 36, and wire cable 26 are connected toan actuator rod 42 of a DC linear actuator 50 (See FIG. 3) by means of acoupling bracket 44. The pulley cap 40, pulley 36, and wire cable 26 areconnected to the coupling bracket 44 by a bolt and nut combination 46passing through holes vertically aligned with the axis of the pulley cap40 and pulley 36. The actuator rod 42 is connected to the couplingbracket 44 by a bolt and nut combination 48 passing through holeshorizontally aligned through the coupling bracket 44 and through thecenter of the outer end of the actuator rod 42.

[0062] The DC linear actuator 50, as shown in FIG. 3, is mounted to thesolid seat base 11 by means of a mounting flange 56 and an actuatormounting piece 52. The actuator mounting piece 52 is mounted to thesolid seat base 11 by two nut and bolt combinations. The mounting flange56 is mounted to the actuator mounting piece 52 by a nut and boltcombination passing through horizontally aligned holes in the mountingflange 56 and first and second vertical portions 54 of the actuatormounting piece 52. The DC linear actuator is positioned so thatdisplacement of the actuator rod 42 is in a direction perpendicular tothe vertical portion of the mounting bracket 32 and centered between thefirst and second circular openings (not shown) in the vertical portionof the mounting bracket 32. In the preferred embodiment, the DC linearactuator 50 is manufactured by Warner Electric, model numberDE12Q17W41-02FHM3HN.

[0063] The DC linear actuator 50 is powered by a twelve-voltrechargeable battery 58 mounted to the bottom of the solid seat base 11.In the preferred embodiment of this invention, the twelve voltrechargeable battery 58 is mounted to the solid seat base 11 by firstand second Velcro straps 59. Each of the first and second Velcro straps59 pass through two slits (not shown) in the solid seat base 11 suchthat each of the first and second Velcro straps 59 pass through thefirst slit (not shown) to the top of the solid seat base 11 and backthrough the second slit (not shown) and around the twelve voltrechargeable battery 58. In the preferred embodiment of this invention,the twelve volt rechargeable battery 58 is a sealed, non-spillable, leadbattery manufactured by CSB Battery Company, Ltd.

[0064] A recharger outlet 68 is mounted to the frame 14 and is wiredacross the positive and negative leads of the twelve volt rechargeablebattery 58. In the preferred embodiment of this invention, the rechargeroutlet 68 is mounted to the rear of the solid seat base 11. However, therecharger outlet 68 can be mounted generally to any part of the frame 14where it is convenient and accessible.

[0065] As shown in FIGS. 3 and 8, the battery power is controlled by adouble throw toggle switch 60 which is mounted to the frame 14. In thepreferred embodiment of this invention, the double throw toggle switch60 is mounted to vertical component 15 of the frame 14. (See FIG. 1.)However, the double throw toggle switch 60 can be mounted generally toany part of the frame 14 where it is convenient and accessible to thewheelchair user. The double throw toggle switch 60 is wired into theelectrical circuit, as shown in FIG. 7, across the positive and negativeleads of the twelve volt rechargeable battery 58. The double throwtoggle switch 60 can be thrown in a first direction 74 or a seconddirection 76. If the double throw toggle switch 60 is thrown in thefirst direction 74, it closes the circuit and powers the motion of DClinear actuator 50 and causes the actuator rod 42 to retract. Theretraction of the actuator rod 42 pulls the pulley 36 and cable wire 26assembly causing the displacement of the cable wire 26 within the cablewire housing 28 in a direction away from the first and second caliperbrakes 18 (See FIGS. 4, 5, and 6 in combination). The displacement ofthe cable wire 26 away from the first and second caliper brakes 18causes equal tension in the cable wire 26 on opposite sides of thepulley 36 and activates the first and second caliper brakes 18 withequal braking force.

[0066] If the double throw toggle switch 60 is thrown in the seconddirection 76, it closes the circuit and the polarity and direction ofcurrent flow through the DC linear actuator 50 is reversed. This powersthe motor of the DC linear actuator 50 in the reverse direction andcauses the actuator rod 42 to extend. The extension of the actuator rod42 displaces the pulley 36 and causes the cable wire 26 to move withinthe cable wire housing 28 toward the first and second caliper brakes 18.This in turn releases the tension in the cable wire 26 created byretracting the activator rod and deactivates the first and secondcaliper brakes 18. The first and second caliper brakes 18 are springbiased (not shown) toward the deactivated position which retains tensionin the cable wire 26 while the actuator rod 42 is extending and preventsbunching of the cable wire 26.

[0067] In order to control the tension in the cable wire 26 when theactuator rod 42 is retracting, a motion limit switch 62 is placed in theelectrical circuit, as shown in FIG. 7, between the positive lead ofdouble throw toggle switch 60. When the double throw toggle switch 60 isthrown in the first direction 74, the motion limit switch 62 limitsmovement of the DC linear actuator 50. The motion limit switch 62 isequipped with a motion arm 64 as shown in FIGS. 3, 6, 7, and 8. Themotion arm 64 is spring biased to contact and press against an actuatingpin 66 as shown in FIGS. 3, 6, 7, and 8. The actuating pin 66 extendsfrom, and is a part of, the coupling bracket 44 as more clearlyillustrated in FIG. 6. The motion limit switch 62 is normally closed.Retraction of the actuator rod 42 causes displacement of the couplingbracket 44 and actuating pin 66, which in turn displaces the motion arm64. Sufficient displacement of the motion arm 64 throws the motion limitswitch 62 opening the circuit and preventing further retraction of theactuator rod 42. The displacement of the motion arm 64 required to throwthe motion limit switch 62 is adjustable to allow for control andselection of the tension in the cable wire 26 and the resulting brakingforce.

[0068] In the normal operation of the wheelchair 10, it is desirable tohave brakes activated during the transfer in and out of the wheelchair10. If the wheelchair user intends to transfer out of the wheelchair, hewill throw the toggle switch 60 in the first direction 74 which causesthe actuator rod 42 to retract and activates the first and secondcaliper brakes 18. The wheelchair user should hold the toggle switch 60in the first direction 74, thereby increasing the braking force appliedby the first and second caliper brakes 18 until the motion limit switch62 is thrown and opens the circuit which stops the retraction of theactuator rod 42. The user should then release the toggle switch 60 whichis spring biased to the center, OFF position. The motor of the DC linearactuator 50 locks the actuator rod 42 in position when there is no powerto the DC linear actuator 50. Thus, the first and second caliper brakes18 will remain activated and hold the wheelchair 10 in position whilethe wheelchair user transfers out of the chair. The first and secondcaliper brakes 18 will remain activated until the toggle switch 60 isthrown and held in the second direction 76 and thereby allowing theactuator rod 42 to extend a sufficient amount to deactivate the firstand second caliper brakes 18 and allow the first and second wheelchairwheels 24 to rotate freely. The toggle switch 60 is then releasedallowing it to spring back to the center OFF position which opens thecircuit and stops the flow of power to the DC linear actuator 50.

[0069] Although the invention has been described with reference tospecific embodiments, this description is not meant to be construed in alimited sense. Various modifications of the disclosed embodiments, aswell as alternative embodiments of the inventions will become apparentto persons skilled in the art upon the reference to the description ofthe invention. It is, therefore, contemplated that the appended claimswill cover such modifications that fall within the scope of theinvention.

I claim:
 1. A wheelchair having quick release, detachable wheels, said wheelchair comprising: a frame; a seat having a bottom portion and a back portion mounted within said frame; a first and second detachable axles mounted to said frame; disk hubs rotatably mounted on said detachable axles; wheel hubs detachably connected to said disk hubs and rotatable therewith; and wheels mounted on said wheel hubs and rotatable therewith;
 2. The wheelchair having quick release, detachable wheels as recited in claim 1 wherein said detachable axles are tubular and further comprise: an inner portion with an exteriorly threaded surface screwably attachable to said frame; an outer portion adjacent said inner portion with a smooth exterior surface for mounting of and rotation thereon of said disk hub; and a flanged portion between said inner portion and said outer portion for shouldering said disk hub when mounted on said detachable axle.
 3. The wheelchair having quick release, detachable wheels as recited in claim 2 wherein each of said disk hubs have at least one projection extending from an outer vertical surface of said disk hubs and each of said wheel hubs having at least one opening in an inner vertical surface of said wheel hub, said at least one projection extending from said disk hubs being insertable into said at least one opening in said wheel hubs.
 4. The wheelchair having quick release, detachable wheels as recited in claim 2 wherein each of said wheel hubs have at least one projection extending from an inner vertical surface of said wheel hubs and each of said disk hubs have at least one opening in an outer vertical surface of said disk hubs, said at least one projection extending from said wheel hubs being insertable into said at least one opening in said at least one disk hubs.
 5. The wheelchair having quick release, detachable wheels as recited in claim 3 or 4 further comprising a pin insertable in said wheel hubs, said disk hubs and said detachable axles, said pin being lockable within said wheel hub, said disk hub, and said detachable axles and also quickly releasable.
 6. The wheelchair having quick release detachable wheels as recited in claim 3 or 4 further comprising a disk mounted on said disk hubs and rotatable therewith.
 7. A quick release, detachable wheel hub assembly for rotating a wheel thereon, said wheel hub assembly comprising: a detachable axle attachable to a frame; an interior hub rotatably mounted on said detachable axle; an exterior hub detachably interlockable with said interior hub and rotatable therewith, said wheel being mountable on said exterior hub for rotation therewith; a pin insertable in said exterior hub, said interior hub, and said detachable axle, said pin being lockable within said exterior hub, said interior hub, and said detachable axle for holding said wheel hub assembly together, said pin also being quickly releasable to disassemble said wheel hub assembly.
 8. The quick release, detachable wheel hub assembly as recited in claim 7 wherein said detachable axle is tubular and further comprises: an inner portion with an exteriorly threaded surface screwably attachable to said frame; an outer portion adjacent said inner portion with a smooth exterior surface for mounting of and rotation thereon of said interior hub; and a flanged portion between said inner portion and said outer portion for shouldering said interior hub when mounted on said detachable axle.
 9. The quick release, detachable wheel hub assembly as recited in claim 8 wherein of said interior hub has at least one projection interlockable with at least one recess in said exterior hub.
 10. The quick release, detachable wheel hub assembly as recited in claim 8 wherein said exterior hub has at least one projection interlockable with at least one recess in said interior hub.
 11. The quick release, detachable wheel hub assembly as recited in claims 9 or 10 wherein said frame is a wheelchair frame.
 12. A method for attaching a wheel to a wheelchair wherein said wheel is quickly detachable comprising the steps of: connecting and fixing a detachable axle to a frame of said wheelchair; first mounting of a disk hub to said detachable axle for rotating thereon; interlocking a wheel hub with said disk hub for rotating therewith; and second mounting of said wheel on said wheel hub for rotating therewith.
 13. The method for attaching a wheel to a wheelchair as recited in claim 12 further comprising the step of locking said wheel hub and said disk hub together with a locking pin wherein said locking pin is quickly releasable to separate said wheel hub and said disk hub.
 14. The method for attaching a wheel to a wheelchair as recited in claims 12 or 13 wherein said detachable axle is tubular and has an exteriorly threaded surface at one end for screwably connecting and fixing said detachable axle to said frame.
 15. The method for attaching a wheel to a wheelchair as recited in claim 14 wherein said detachable axle also has a smooth surface at an end opposite said exteriorly threaded surface for said first mounting of said disk hub.
 16. The method for attaching a wheel to a wheelchair as recited in claim 15 wherein said disk hub has at least one projection extending from an outer vertical surface of said disk hub and said wheel hub has at least one opening in an inner vertical surface of said wheel hub, said at least one projection extending from said disk hub being insertable into said at least one opening in said wheel hub.
 17. The method for attaching a wheel to a wheelchair as recited in claim 15 wherein said wheel hub has at least one projection extending from an inner vertical surface of said wheel hub and said disk hub has at least one opening in an outer vertical surface of said disk hub, said at least one projection extending from said wheel hub being insertable into said at least one opening in said disk hub.
 18. A method for attaching a wheel to a frame wherein said wheel is quickly detachable from said frame comprising the steps of: connecting a detachable axle to said frame wherein said detachable axle is tubular and has an exteriorly threaded surface at one end for said connecting said detachable axle to said frame, said detachable axle having a smooth surface at an opposite end from said exterior threaded surface; first mounting of an interior hub on said smooth surface of said detachable axle for rotation thereon; interlocking an exterior hub with said interior hub for rotation therewith wherein said exterior hub is quickly detachable from said interior hub; and second mounting of said wheel on said exterior hub for rotation therewith.
 19. The method for attaching said wheel to said frame as recited in claim 18 further comprising the step of locking the said exterior hub to said interior hub with a locking pin, said locking pin being quickly releasable to separate said exterior hub from said interior hub.
 20. The method for attaching said wheel to said frame as recited in claim 19 wherein said locking pin is insertable into said exterior hub and said interior hub.
 21. The method for attaching said wheel to said frame as recited in claim 18 wherein said exterior hub has at least one projection interlockable with at least one recess in said interior hub.
 22. The method for attaching said wheel to said frame as recited in claim 18 wherein said interior hub has at least one projection interlockable with at least one recess in said exterior hub. 